The South Pacific island kingdom of Tonga has been paralysed for a sixth day by striking public sector workers.

Civil servants and government employees started the industrial action, demanding pay increases of up to 80%.

The strikes have now spread, with many teachers, doctors and nurses walking off the job and local media putting the numbers of protestors at about 3,000.

The government said it cannot afford the higher wages. Tonga's finances have been in trouble for years.

'Break the windows'

According to local press reports, an attempt to reach a compromise between the strikers' representatives, the Public Servants Association (PSA), and the government failed.

The government has said it is looking into the demands of the workers, but warned that a significant pay hike could damage the local economy by boosting living costs, local media reported.

Finau Tutone, chair of the PSA, was quoted by the Matangi Tonga website as saying that the situation was tense and warned that it may turn violent.

If the government "close their doors for negotiations or talking, I'm afraid the people are not going to be suffocated in the house", he said.

"They may break the windows and doors, in order to get some air."

Go slow

The strike has closed down large parts of the island, with schools having to close and goods not being delivered or loaded.

"There is more and more cargo piling up on the wharf," said Sione Ngongo Kioa, president of the Tonga Chamber of Commerce and Industries.

Tonga's main hospital has lost about 40% of its workforce and the president of the Tonga Medical Association, Dr Siale Akau'ola, said that the main hospital in the capital was only treating emergencies.

"It's not only the doctors," he said. It's "other paramedical staff, like radiology, technicians and some of the laboratory staff, and the maintenance staff".

Tonga's finances have been hit by mismanagement and scandals.

In 2001, two cabinet ministers were forced to quit because about $26m disappeared after it was invested in a company by the king's official court jester.

Since then, other money has been lost in ill-fated overseas investments and the national airline has collapsed.